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March 27, 1951 Filed Oct 9, 1945 March 27, 1951 R. E. FARNSWORTHAUTOMATIC LIQUID DRAIN 2 Sheets-Sheet 2 Filed Oct. 9, 1945 INVENTOR R.E-E IRNSWORTH ATTORN EY Patented Mar. 27, 1951 UNITED STATES rATENT OFFICE8 Claims.

The invention relates to a device for draining means for effecting theremoval of any liquid without involving a loss of gas or the lowering ofits pressure.

Another object is to provide a liquid drain device which is constantlyconditioned for the automatic removal of liquid from a chambercontaining a gas under relatively high pressure.

A more specific object is to provide for the removal of liquid from apurging or liquid-trapping tank of a gas-compressing system.

The invention possesses other objects and features of advantage, some ofwhich, with the foregoing, will be set forth or be apparent in thefollowing description thereof, and in the accompanying drawings, inwhich,

Figure l is an elevation of a gas-compressing system embodying thefeatures of present inven provided chemically or electrolyticallyusually contain water vapor or other vapors 01' gases which may condenseunder the pressure finally imposed on the gas being compressed. Thepresent method and means has been particularly designed forautomatically removing any liquid from the bottom of a purge tank or thelike without any loss of the gas or affecting the pressure in thecompressor system including the tank, it being noted that compressionpressures up to 3,000 pounds per square inch are frequently usedcharging free containers with compressed gas.

In the illustrated apparatus, the bottom l3 of the tank It is formed asa liquid-collecting basin having a bottom drain opening at which a drainpipe !5 is connected, said pipe having a T fitting tion, portions ofcertain elements of the apparatus being shown in section. 7

Figure 2 is an enlarged fragmentary sectional view at the stepped line2-2 in Figure 1.

Figure 3 is a top view of a liquid trap element of the apparatus, theview being taken at the line 33 in Figure 1.

Figure 4 is a fragmentary sectional elevation taken at the line 4- 3 inFigure 3.

Figure 5 is a section at the line 5-5 in Figure 4.

Figure 6 is an enlarged fragmentary view at a balance beam of thesystem, liquid and gas valves of the structure being shown in axialsection, and said valves being conditioned as when the liquid-removingmeans is inoperative.

Figure 7 is a view similar to Figure 5, but shows the liquid valveconditioned for a liquid flow therethrough and the gas valve in sideelevation.

The liquid-draining device of my invention is particularly disclosed asbeing applied in a gascompressing system wherein a compressor II ofmulti-stage type is arranged to supply compressed gas through a pipe i2into a tan; 83 from which the gas may be distributed under pressurethrough a discharge pipe it while any liquid carried by the inflowinggas collects in the bottom of the tank, such a tank being known in theart as a distributing or purge tank. One usual source of liquiddeposited in a purge tank is the lubricant used in the compressor; saidlubricant may, for instance, comprise water or an aqueous soap solutionused as a lubricant in compressors for oxygen, or other lubricants usedin compressors for other gases. Furthermore, air or supposedly puregases interposed therein at its lower point and having the lowestopening thereof closed by a screw plug It; the plug it may be removedfor a gravity draining of the tank l3 when the tank pressure isrelatively low or completely relieved. A normally open shut-off valve His provided in the pipe l5 for closing when the pipe i5 is not to beused or when the tank 13 is to be drained by a removal of the screw plugit. The gas supply pipe i2 is shown as extending substantially to thebottom of the tank cavity, While the tank discharge pipe It extends froman upper point of the tank cavity; this is a usual arrangement for purgetanks receiving and discharging gases under pressure and facilitates theseparation of any liquid from the incoming gas.

The drain pipe [5 discharges into a gravity trap unit l8, and the top ofthe trap cavity is connected by means of a pipe 26 through a normallyopen valve 59 and a valve 25 to atmosphere or to the intake 22 for thecompressor, the latter being shown. The bottom of the trap cavity isconnected by a pipe 23 to a valve 24 through which trapped liquid may bedischarged through a pipe 25 under atmospheric pressure and into a pipe26 through which the liquid may be conveyed to apoint where it is wastedor used; the pipe 26 is shown as comprising a stand-pipe providing afunnel 26 at its top for receiving liquid falling from the bottom end ofthe pipe 25. It will be understood that the trap unit it and valve itare interposed in the liquid flow line provided by the pipes 15 and 23and 25 taken in order.

It will now be particularly noted that the trap unit it comprises aflask member 21 providedwith a bail 28 by which it is suspended from oneend of a, beam member 29 which is pivotally supported at an intermediatepoint thereof from a fixedly disposed hanger 3|, the beam being atelyadjacent their connections to the flask maintained in a generallyhorizontal position by a suitable means such as a counterweight 32mounted on its other end. The present counterweight 32 comprises acylindrical bucket which is provided with a supporting bail 33 which itis hung on the beam end, and the cavity of the counterweight 32 maycontain sand 36 and/or other suitable materials for providing anadjusted counter-balancing of the flask unit for its lowering after apredetermined weight of liquid is in the flask cavity. The weight ofliquid required in the container 2? for lowering the trap unit it ispreferabl such as will substantially half. fill the container, and sucha lowering of the trap unit is arranged to open the normally closedvalve 2 for the escape of liquid through the pipes 23 and 25 at a ratedetermined by the degree of opening of the valve 24 operating as aneedlevalve.

To permit the required up and down move- .ment of the trap .unit, itsconnections with the pipes 15 and 2t and 23 must be appropriatelyflexible and offer aminimum or" resistance to the movement of the trapunit as the amount of liquid therein varies. ,As particularlyillustrated, portions of the pipes 55 and 25 immediill are respectivelyformed as helical coils l and 20' which have their axes substantiallyparallel to the upright line of possible movement of the trap unit andoffer a minimum resistance to such .movement; the present coils i5 and20' are axially aligned and generally alike whereby an axial compressionof one is generally compensated for by a like axially stretching of theother as the tra ,unit moves.

The liquid discharge pipe 23 is given the required flexibility theprovision therein of. a helical portion 23', having its axis generallyperpendicular to the line of movement of the trap unit. The pipes l5 and2e and 23 may comprise relatively small and flexible tubing of requiredstrength for the pressures which may exist therein.

In the disclosed trap structure, the connections for the pipes 15 and 28and 23 are provided through a plug or cork 35 sealediy fixed in the neck2'? of the flask 21, and said neck provides oppositely directed earsttto which the ends of the bail 28 are rigidly attached by and betweennuts 3! threadedly engaging the ears. The top of the bail 28 isswingaoly looped over a suitable seat provided across onebeam end, asininar mounting being provided for the counterweight bail at the otherbeam, end. lvlutually aligned trunnions 38 extend oppositely from anintermediate point of thebeam 29 above the center of gravity of the beamand its load, said trunnions providing downwardly-directed knife edges38 for engaging seats at the bottoms of V notches 39 provided by membersll or the han er 3 By particular reference to the showings of Figures 2and 6, it will be noted that the present hanger 3% comprises a-basemember by which the hanger may be secured to a fixed support (notshown), and the members ll, which are generally C-shaped, are. bolted tothe base at transverse flange portions 4! at their tops and provide. thenotches 3?; at top points of their lower ends to provide a horizontalsupport axis for the beam. The hanger members ll mount the valve 2 by aclamped engagement of the valve body 2 2' between them in adjusted posi---tion in a generally horizontal line; bolts 13 extend through" andbetween the hanger members 45 for securing the valve body in alongitudinally adjusted position on the hanger.

The body 2d of the valve 2% is generally tubular and has a stepped boreproviding a seat for the conical tip of a reciprocable valve plug Hwhich is movable through the larger bore portion, the valve assemblyfunctioning as a needle valve. A compression connection a5 is providedfor the pipe 23 at the extremity of the smaller bore portion, thearrangement'being such that the pressure in the pipe 23 is arranged tourge an unseating of the valve plug it. The larger body bore portion isenlarged immediately adjacent the valve seat, and the pipe is connectedto the body at said enlarged bore portion for a lateral discharge or"liquid from t. e body through i this pipe. The stem of the plug litextends axial" viding a flat plug-contacting face in a plane whichpreferably includes the axis of 1y from the valve body 24 through asuitable packing or stuffing box it.

It will now be noted that the extending end of the valve plug l -liearranged for its constant bearing engagement with an upward extension orarm :31 of the beam 29, said extension proil extending swinging andcenter of gravity of the beam. When no liquid is to escape through thevalve 24, the beam is arranged to be so positioned that the beamextension ll is operative to hold the valve shut against any liquid flowfrom the pipe '23. When the beam is rocked by reason of the sufficientaccumulation of liquid in the flask '2? to pull down the beamend whichcarries the flask, the needle valve plug it is released for its pressuredispl cement to the escape of liquid through and from the pipe 25.

The valve is is arranged to be open continuously during the operation ofthe present apparatus for effecting a very slight relief 0: the tankpressure through the pipe ill whereby the tank pressure may cause theexpulsion of liquid from the bottom of the tank through the pipe portionleading to the flask Z? for its trapping in the'fiask. It willbe'understood that t. e pressure in the trap system is arranged to bejust enough lower than that in the tank l3 that the pressuredifierential between the tank and flask is sufficient to expel liquidfrom the tank bottom as it is deposited thereat, said liquid beingaccompanied by a certain amount of the gas for escape through the valveIt in accordance with the setting of the latter.

The valve 2i normallyprovides an open passage for the gas therethroughand arranged to be automatically closed by the action of the beam 2% ascontrolled by the position of the trap unit when the flask containsappreciably more than .the desired limited amount of liquid, as

may tend to occur on account of a pressure discharge of liquid from thebottom of the tank E3 following an accumulation of liquid in the tank 53while there is no liquid flow through the apparatus, it being necessarythat the liquid level in the flask be prevented from reaching the flaskoutlet to the pipefit through which gas normally escapes from the flaskto, and through the valve Hi. When the valve ii is closed, the valve 2:3is fully open, whereby the tank pressure will force the liquid from thetrap to eventually so lower the liquid level in the trapas topermit araising of the unit under the influence of the counterweight 32 tofinally eilect an'opening of the valve 21 for the resumption of gas flowthrough the valve is and the func ioning of the rimary automaticcontrbl.-It will-be understood that when the present apparatus is operating forcompressing a gas and delivering the same through the tank l3, the trapunit will constantly hunt a position in which the drainage actiontherethrough is generally continuous, whereby the action comprises anautomatic weighing-out process, and the bottom of the tank I3 is keptclear of liquid.

The present valve 2! comprises a body having threadeolly engagedsections it and defining a chamber 5! which is partitioned by a flexiblediaphragm or disc Inlet and discharge openings 53 and 5 are provided inthe bottom of the section 49 at tubular nipples for connecting the valveat a point in the pipe 23 between the valve 19 and the compressor intake22. The inlet opening 53 is opposite the center of the disc 52 andterminates in a tubular boss 55 providing a valve seat at its endagainst which the disc is arranged to be mechanically engaged to closethe gas escape line from the flask through the valve l9 and so preventany fiow of liquid into the pipe 20.

The diaphragm 52 is normally spaced from the boss 55, and a member 56 isslidably engaged through the section id for projection against thediaphragm center to positively seat a diaphragm against tie boss in itspassageclosing position. The member 5% has a discengaging head 56' and asmaller stern portion 56 extending from the section 48 for depressingengagement when the passage through the valve is to be closed. In theassembly of the present apparatus, the valve 2i is fixedly mounted withthe upper end of its stem 5%" disposed for displacing engagement by thebeam arm which carries the trap unit should the flask of the unitcontain more than a permitted weight of liquid. The valve 2! may befixedly supported in its operative position in any suitable manner, itsvertically adjusted support from an arm 5? depending from a hangermember ll being particularly shown whereby this valve is unitarilyassociated with the valve 2 It will now be particularly noted andunderstood that the present device is usable in connection with purgetanks from which many different kinds of gases are supplied forsupplying free containers with the gas. For example, a gas to be sohandled may comprise acetylene, oxygen, nitrogen, helium, hydrogen,sulphur dioxide, carbon dioxide, and others, most of such gases beingeither injurious to life and/or being too valuable to waste; thedisclosed connection of the pipe 20 to the intake of the compressor iiis therefore usually desirable as a means to salvaging the gas escapingthrough the valve l9. Also, in

applying the present device to gas-compressing systems handlingdifferent gases, the delivery pressures of the different gases handledmay vary considerably, hence the disclosed use of a regulator type valvefor controlling the gas and liquid flow to and through the weighing-outflask 2? provides for a ready adaptation of the same device tohigh-compression apparatus for different gases by reason of thepermitted adjustability of the valve [9 to provide an appropriateliquid-purging action with respect to a tank l3.

From the foregoin description taken in connection with the accompanyingdrawings, the advantages of the construction and use or" the presentdevice will be readily understood by those skilled in the art to whichthe invention appertains. While I have described the principle ofoperation, together with an arrangement which 6 I now consider tocomprise a preferred embodiment thereof, I desire to have it understoodthat the disclosure is primarily illustrated, and that such changes anddevelopments may be made, whendesired, as fall within the scope of thefollowing claims.

I claim:

1. In combination with a vessel in a flow line for compressed gas and inwhich liquid carried by the gas may be deposited, a discharge pipe forthe deposited liquid, a liquid-discharge valve for said pipe, a liquidtrap interposed in said pipe between its discharge valve and the vesselto receive the liquid, mealns supporting said trap for its loweringdisplacement as a unit when the trap contains more than a predeterminedweight of the liquid, and means utilizing the position of the trap to socontrol said liquid-discharge valve that the weight of liquid in thetrap is automatically held to a predetermined value.

2. In combination with a flow line for compressed gas, a vesselproviding a basin in which liquid carried by the gas may be deposited, afluiddischarge pipe from the bottom of the basin, a

liquid-discharge valve in said pipe, a liquid trap interposed in saidpipe, and a valve means providing for a regulated constant and limitedescape of gas from the trap whereby the fluid pressure in the trap ismaintained at a value very slightly less than that of the vessel toprovide a continuous limited flow of gas with the deposited liquid fromthe vessel into the trap while its normal gas pressure is maintained inthe vessel and the liquid-discharge valve is open.

3. In combination with a flow line for compressed gas, a vesselproviding a basin in which liquid carried by the gas may be deposited, afluid-discharge pipe from the bottom of the basin, an adjustableliquid-discharge valve in said pipe, a liquid trap interposed in saidpipe, a gas-discharge pipe leadin from said trap, and a regulator valvemeans in said gas-discharge pipe providing for a constant and adjustablylimited escape of gas therethrough from the trap whereby the trappressure is enough lower than the pressure in the vessel as .to providea continuous and limited flow of gas and the deposited liquid from thevessel into the trap.

4. In combination with a flow line for 06hpressed gas, a vesselproviding a basin in which liquid carried by the gas may be deposited, ailuid-discharge pipe from the bottom of the basin, a liquid-dischargevalve in said pipe, a unitary liquid trap interposed in said pipe andyieldingly supported for its lowering when it c0ntains a predeterminedweight of liquid, means providing for a constant and limited escape ofgas from the trap for producin a flow of gas with deposited liquid fromthe vessel thereinto, and means whereby a lowered disposal of said trapconditions the liquid-discharge valve for the discharge of the liquidfrom the trap at a uniform rate when and while the weight of liquid inthe trap has a predetermined value.

5. In combination with a flow line for highly.

compressed gas, a vessel providing a basin in which liquid carried bythe gas may be depos. ited, a fluid-discharge pipe from the bottom ofthe basin, a liquid-discharge valve in said pipe, a liquid trapinterposed in said pipe, a gas-dis charge pipe leading from said trap, avalve means in said gas-discharge pipe providing for a constant andadjustably limited escape of gas therethrough from the trap, meanssupporting said trap for its lowering as a unit when the weight ofliquidtherein reaches a predetermined value, and means for actuation by thelowered trap to open the liquid-discharge valve for the discharge ofliquid from the trap by the action of the trap pressure.

6. A structure in accordance with claim 5 wherein the means supportingthe trap for its lowering for opening the liquid-discharge valvecomprises a counterbalanced beam member.

7. In combination with a flow line for compressed gas, a vesselproviding a basin in which liquid carried by the gas maybe deposited, afluid-discharge pipe from the bottom ofthe basin, a liquid-dischargevalve in said pipe, a liquid trap interposed in said pipe, agas-discharge pipe leading from said trap, means in said gas-dischargepipe providing for a constant and limited escape of gas therethroughfrom the trap, means supporting said trap for its lowering when theWeight of liquid therein exceeds a predetermined value, means for normalactuation by the lowered trap to open the liquid-discharge valve for thedischarge of liquid from the trap by the action of the trap pressure,and means automatically operative to close said gas-discharge pipebeyond said opening when the weight of liquid in the trap substantiallyexceeds that required for ef- REFERENCES CITED The following referencesare of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 399,427 Moore Mar. 12, 1889609,284 Losure Aug. 16, 1898 855,243 Green et al. May 28, 1907 925,438Mount June 15, 1909 1,450,561 Parker Apr. 3, 1923 1,547,429 Ludeman July28, 1925 1,581,636 Hilger Apr. 20, 1926 1,941,030 Williams Dec. 26, 19331,995,075 Murphy Mar. 19, 1935

